Hypertension affects nearly 70 million Americans, and is effectively controlled in less than half. Because uncontrolled hypertension is a leading cause of stroke, congestive heart failure, renal disease, and myocardial infarction, development of cost-effective and scalable hypertension control strategies has been identified as an urgent national priority. The NHLBI-funded randomized HyperLink trial (Home Blood Pressure Telemonitoring and Case Management to Control Hypertension) has developed and implemented a very effective yet simple two-step non-office-based blood pressure (BP) control strategy: (a) patients measured BP at home using telemonitors that stored and electronically transmitted BP data to a pharmacist via a telephone modem, (b) In periodic telephone visits, pharmacists advised patients on medication adherence and lifestyle, and adjusted antihypertensive therapy under a collaborative practice agreement with primary care physicians. This simple strategy has now been rigorously evaluated in a randomized trial in which it doubled the proportion of patients who achieved and maintained BP control at both 6 and 12 months following enrollment (31.4% in usual care and 58.5% in the intervention group, P=.0002). It achieved systolic BP 11 mm Hg lower (P<0.0001) and diastolic BP 5 mm Hg lower (P=0.02) in the intervention group compared to the usual care group at 12-month follow-up. The purpose of this proposal is to extend follow-up of the 450 patients enrolled in the HyperLink intervention and usual care groups to achieve three specific aims: (a) provide new data on the long-term durability (b) assess the cost-effectiveness of the Hyperlink intervention, and (c) use mixed methods to identify critical factors for delivering the intervention successfully and translating i into practice. All patients will be invited to attend two research clinic visits to measure BP at tme points 36, 48, and 60 months following enrollment. Extended data will include serial assessments of BMI, antihypertensive treatment and adherence, use of home BP monitoring, satisfaction with medical care, and surveillance for clinical cardiovascular events. Long-term health impact and cost-effectiveness will be quantified using directly observed measures and state-of-the-art microsimulation prediction modeling of cardiovascular events and treatment costs. Focus groups and semi- structured interviews with study subjects, pharmacists, and health system stakeholders will provide additional perspectives on 1) optimizing successful delivery of the intervention, and 2) on strategies and barriers for translation into clinical practce. These results will fill critically important knowledge gaps and provide practical information about the costs and benefits of implementing a this scalable and effective new care model that holds great promise for improving outcomes for millions of Americans with uncontrolled hypertension.